SQL Query Explainer Skill

This skill explains SQL queries in plain language, identifies optimisation opportunities, and helps communicate data logic to non-technical stakeholders. It also writes and documents new queries from natural language descriptions.

Required Inputs

• The SQL (Explain/Optimise/Document modes) — the actual query, ideally with the dialect named (Postgres, BigQuery, Snowflake, MySQL…); dialect changes both semantics and the optimisation advice.
• The intent in plain words (Write mode) — what question the data should answer, plus table/column names if known. Without a schema, assumptions get stated, never silently invented.
• Optional but transformative: EXPLAIN/EXPLAIN ANALYZE output and rough table sizes — turns generic advice into advice about your query plan.

Modes

Detect which mode the user needs based on their request:

1. Explain — Translate existing SQL into plain English
2. Optimise — Review SQL for performance issues and suggest improvements
3. Write — Generate SQL from a natural language description
4. Document — Produce a data dictionary or query documentation